Ala-
From Tolkien Gateway
ala- is a Quenya prefix meaning "not-, un-". Seen in alahasta "unmarried"[1]. This prefix seems to have the power to turn a following verbal stem into a past participle even if no explicit participle ending is present. Unlike ú-, this prefix does not seem to have negative connotations.
References
- ↑ J.R.R. Tolkien, Christopher Tolkien (ed.), Morgoth's Ring, p.254